Aquatic sports board

ABSTRACT

A semi-submersible aquatic sports board having a primary load supporting region which is substantially more buoyant and has a greater vertical dimension than other regions of the board. The board may comprise a curved hull, a keel projecting downwardly from the hull and a deck positioned on an upper surface of the hull for supporting a rider in the primary load supporting region. In one embodiment the board may be propelled by a rider supported on the deck in a prone position by using motions similar to natural swimming strokes. The rider can initiate pivoting motion of the board about an axis aligned with the primary load supporting region to aid in self- propulsion. Optionally tail accessories, such as fins, can be coupled to a stern end of the keel and/or hull. At a narrow forward end of the hull the board may include opposed side rails having a pronounced upward curve which merge at a nose at the bow end. The rails may define a viewing opening therebetween.

REFERENCE TO RELATED APPLICATIONS

This application claims priority on U.S. provisional patent application No. 62/163,587 filed 19 May 2015 which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

This application relates to boards and crafts for supporting a rider. In some embodiments the application relates to aquatic sports boards and personal watercrafts which are designed for human-powered propulsion.

BACKGROUND

Surf boards and body boards are generally designed for riding waves, from which much of the propulsion power for the board is derived. They are not generally designed for use in water where there are no significant waves. Consequently, they have not been optimized to be propelled by the arms and legs of the rider.

Because of their overall shape, and the necessary riding positions of the rider, surfboards, body boards and kickboards must be propelled using a paddling motion in which the arms are bent out to the sides in order to move past the outer edge of the board. This motion is significantly less effective than the more efficient motions used in conventional swim strokes such as freestyle, breast stroke and butterfly.

The use of the rider's legs to kick effectively in the case of surfboards, body boards and kick boards is also limited. Body boards and kick boards do allow for the use of the rider's legs, but because the rider's pelvis is not well supported, the power of the kick stroke is reduced, and the board must be held with the arms in order for the legs to generate more power. Furthermore, because body boards and kick boards tend to be of roughly equal thickness throughout most of their length, and lack substantial thickness and buoyancy at their stern, where much of the rider's weight bears down on the board, it is very difficult for the rider to raise their hips up and lower their shoulders to create more power, without the weight of the rider sinking the board too deeply into the water to be effective. Added to this, the overall flatness of the decks of surf boards, body boards and kick boards does not facilitate the effective use of the rider's torso muscles, commonly referred to as core muscles, to aid in the propulsion of the board.

Furthermore, the lack of buoyancy and curvature in the bow regions of surf boards, body boards and kickboards restrict the degree to which the rider can position themselves close to the bow, where the board is ordinarily narrower, for fear of nose-diving the board.

The present application relates to a buoyant aquatic sports board on which the rider is more effectively supported in a wide variety of positions, is able to pivot the angle of the board more effectively, for example about its stern, and can use their arms, legs, abdominal muscles, torso and spine in a more natural, powerful and effective way to propel the board forward.

The foregoing examples of the related art and limitations related thereto are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.

SUMMARY

The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools and methods which are meant to be exemplary and illustrative, not limiting in scope. In various embodiments, one or more of the above-described problems have been reduced or eliminated, while other embodiments are directed to other improvements.

One aspect of the invention provides an aquatic sports board deployable in water and having a bow end and a stern end, wherein the board comprises a buoyant hull having a lower portion which is at least partially curved between the bow end and said stern end, and wherein the board comprises a primary load supporting region having a sufficient volume for buoyantly supporting a substantial proportion of the weight of a rider at or near the surface of the water. Preferably the primary load supporting region comprises at least part of the hull and has a vertical dimension larger than other parts of the hull. The primary load supporting region may be substantially larger in volume than other regions of the board.

The primary load supporting region may be located toward the stern end of the board. The board may be pivotable relative to an axis aligned with the primary load supporting region to cause pitching, rolling and/or yawing motion of the board.

When the board is deployed in water, the primary load supporting region may be configured to support the rider in a riding position wherein the rider is able to move both their arms and legs through the water to propel the board using swimming motions. In one aspect, in at least some of the riding positions, the primary load supporting region is configured to support the hips of the rider at an elevation approximately even with the chest of the rider.

The primary load supporting region may also comprise a deck located on an upper surface of the hull and at least part of a keel projecting from the lower surface of the hull. The hull may include a rear portion comprising an enlarged portion of the hull and a forward portion which curves upwardly from the rear portion to a nose located at the bow end of the board.

In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and by study of the following detailed descriptions.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments are illustrated in referenced figures of the drawings. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than restrictive.

FIG. 1 is a side view of an embodiment of the applicant's aquatic sports board deployed in water showing a rider in an exemplary riding position.

FIG. 2 is a side view of the board of FIG. 1 showing the rider in a more body-forward riding position.

FIG. 3 is a top isometric view of an embodiment of the applicant's sports board;

FIG. 4 is a bottom isometric view of the board of FIG. 3;

FIG. 5 is a top plan view of the board of FIG. 3;

FIG. 6 is a bottom plan view of the board of FIG. 3;

FIG. 7 is a right side elevational view of the board of FIG. 3;

FIG. 8 is a left side elevational view of the board of FIG. 3;

FIG. 9 is a front elevational view of the board of FIG. 3;

FIG. 10 is a rear elevational view of the board of FIG. 3;

FIG. 11 is an enlarged, exploded view of a mounting slot and plug;

FIG. 12 is an enlarged, exploded view of a mounting slot and tail accessory;

FIG. 13 is a bottom isometric view of a first tail accessory;

FIG. 14 is a top isometric view of the first tail accessory of FIG. 13;

FIG. 15 is a bottom isometric view of a second tail accessory;

FIG. 16 is a top, isometric view of the second tail accessory of FIG. 15;

FIG. 17 is a bottom isometric view of a third tail accessory;

FIG. 18 is a top isometric view of the tail accessory of FIG. 17;

FIG. 19 is a top isometric view of the board of FIG. 3 fitted with the first tail accessory of FIG. 13;

FIG. 20 is a bottom isometric view of the board of FIG. 19;

FIG. 21 is a top plan view of the board of FIG. 19;

FIG. 22 is a bottom plan view of the board of FIG. 19;

FIG. 23 is a right side elevational view of the board of FIG. 19;

FIG. 24 is a left side elevational view of the board of FIG. 19;

FIG. 25 is a front elevational view of the board of FIG. 19;

FIG. 26 is a rear elevational view of the board of FIG. 19;

FIG. 27 is a top isometric view of the board of FIG. 3 fitted with the second tail accessory of FIG. 15;

FIG. 28 is a bottom isometric view of the board of FIG. 27;

FIG. 29 is a top plan view of the board of FIG. 27;

FIG. 30 is a bottom plan view of the board of FIG. 27;

FIG. 31 is a right side elevational view of the board of FIG. 27;

FIG. 32 is a left side elevational view of the board of FIG. 27;

FIG. 33 is a front elevational view of the board of FIG. 27;

FIG. 34 is a rear elevational view of the board of FIG. 27;

FIG. 35 is a top isometric view of the board of FIG. 3 fitted with the third tail accessory of FIG. 17;

FIG. 36 is a bottom isometric view of the board of FIG. 35;

FIG. 37 is a top plan view of the board of FIG. 35;

FIG. 38 is a bottom plan view of the board of FIG. 35;

FIG. 39 is a right side elevational view of the board of FIG. 35;

FIG. 40 is a left side elevational view of the board of FIG. 35;

FIG. 41 is a front elevational view of the board of FIG. 35;

FIG. 42 is a rear elevational view of the board of FIG. 35;

accessory of FIG. 15

FIG. 43 is a top isometric view of another embodiment of the applicant's aquatic sports board;

FIG. 44 is a bottom isometric view of the board of FIG. 43;

FIG. 45 is a top plan view of the board of FIG. 43;

FIG. 46 is a bottom plan view of the board of FIG. 43;

FIG. 47 is a right side elevational view of the board of FIG. 43;

FIG. 48 is a left side elevational view of the board of FIG. 43;

FIG. 49 is a front elevational view of the board of FIG. 43;

FIG. 50 is a rear elevational view of the board of FIG. 43;

FIG. 51 is a top isometric view of another embodiment of the applicant's aquatic sports board;

FIG. 52 is a bottom isometric view of the board of FIG. 51;

FIG. 53 is a top plan view of the board of FIG. 51;

FIG. 54 is a bottom plan view of the board of FIG. 51;

FIG. 55 is a right side elevational view of the board of FIG. 51;

FIG. 56 is a left side elevational view of the board of FIG. 51;

FIG. 57 is a front elevational view of the board of FIG. 51;

FIG. 58 is a rear elevational view of the board of FIG. 51;

FIG. 59 is a top isometric view of another embodiment of the applicant's aquatic sports board;

FIG. 60 is a bottom isometric view of the board of FIG. 59;

FIG. 61 is a top plan view of the board of FIG. 59;

FIG. 62 is a bottom plan view of the board of FIG. 59;

FIG. 63 is a right side elevational view of the board of FIG. 59;

FIG. 64 is a left side elevational view of the board of FIG. 59;

FIG. 65 is a front elevational view of the board of FIG. 59;

FIG. 66 is a rear elevational view of the board of FIG. 59;

FIG. 67 is a top isometric view of another embodiment of the applicant's aquatic sports board similar to the embodiment of FIG. 59 and including a rail cover;

FIG. 68 is a bottom isometric view of the board of FIG. 67;

FIG. 69 is a top plan view of the board of FIG. 67;

FIG. 70 is a bottom plan view of the board of FIG. 67;

FIG. 71 is a right side elevational view of the board of FIG. 67;

FIG. 72 is a left side elevational view of the board of FIG. 67;

FIG. 73 is a front elevational view of the board of FIG. 67;

FIG. 74 is a rear elevational view of the board of FIG. 67;

FIG. 75 is a top isometric view of another embodiment of the applicant's aquatic sports board configured as a stand-up paddle board;

FIG. 76 is a bottom isometric view of the board of FIG. 75;

FIG. 77 is a top plan view of the board of FIG. 75;

FIG. 78 is a bottom plan view of the board of FIG. 75;

FIG. 79 is a right side elevational view of the board of FIG. 75;

FIG. 80 is a left side elevational view of the board of FIG. 75;

FIG. 81 is a front elevational view of the board of FIG. 75;

FIG. 82 is a rear elevational view of the board of FIG. 75;

FIG. 83 is a rear elevational view of the board of Figure X having a closeable compartment;

FIG. 84 is a bottom isometric view of the board of Figure Y fitted with hydrofoil accessories.

DESCRIPTION

Throughout the following description specific details are set forth in order to provide a more thorough understanding to persons skilled in the art. However, well known elements may not have been shown or described in detail to avoid unnecessarily obscuring the disclosure. Accordingly, the description and drawings are to be regarded in an illustrative, rather than a restrictive, sense.

This application relates to an aquatic sports board generally designated 10. In some embodiments, board 10 includes a hull 12, a keel 14 projecting from an undersurface of hull 12 and a deck 16 located on an upper surface of hull 12 for supporting a rider. As described in detail below, hull 12, keel 14 and deck 16 are buoyant for supporting the rider in a wide variety of riding positions when board 10 is deployed in water.

The angle at which board 10 rests in in the water can vary significantly, As used in this patent application, spacial or directional terms such as “upper”, “lower”, “under”, “over”, “forward” and “rear” and the like refer to elements of board 10 when oriented in a typical riding position in calm water. FIGS. 1 and 2 illustrate board 10 in two exemplary riding positions. As used in this patent application “riding positions” include positions where the rider is actively propelling board 10 using swimming motions and also positions where the rider is at rest and/or is harnessing waves, current, wind or other external forces for causing motion of board 10. FIG. 1 illustrates board 10 in a riding position with the rider's head slightly raised. FIG. 2 illustrates board 10 in a riding position with the rider's body shifted forwardly on board 10 and the rider's head in a less raised posture. As will be appreciated by a person skilled in the art, and as discussed further below, many other orientations of board 10 are possible depending upon the particular riding position adopted by the rider and the prevailing water conditions.

In some embodiments board 10 includes a primary load supporting region 18 for supporting a substantial proportion of the weight of the rider, such as the weight of the rider's lower torso, hips (pelvis) and upper legs at or near the surface of the water (FIGS. 1 and 2). As discussed in detail below, such body regions of a rider are ordinarily considerably heavier and less buoyant than the remainder of their body. Unlike conventional surf boards and body boards which typically have a substantially uniform thickness, primary load supporting region 18 is configured to be substantially larger in volume and consequentially substantially more buoyant than other regions of board 10. Also, primary load supporting region 18 is preferably configured to have a vertical dimension greater than other regions of board 10. As used in this patent application the term “buoyant” refers to a structure which produces a buoyant force when it is at least partially immersed in water. For example, primary load supporting region 18 may comprise a portion of hull 12, keel 14 and/or deck 16 which produces a buoyant force directed to load supporting region 18 sufficient to support a substantial proportion of the weight of rider, such as their lower torso, hips and upper legs, in a riding position at or near the surface of the water.

As shown in FIGS. 1 and 2, in use board 10 is designed to be semi-submersible. That is, a substantial proportion of board 10, including a substantial proportion of load supporting region 18, is ordinarily immersed below the waterline when the rider is positioned on board 10 in a riding position. Board 10 may also include one or more secondary load supporting regions 20 for supporting other portions of a rider's body in a riding position, such as their upper torso.

Due to the structure of board 10 as described herein, primary load supporting region 18 can be controllably pivoted or articulated by a rider. For example, in some embodiments described herein region 18 includes a curved portion of hull 12, a deck 16 positioned on hull 12 for supporting the rider, and an enlarged portion of keel 14 projecting downwardly from hull 12 beneath deck 16 and in line with the longitudinal centerline of board 10. The enlarged portion of the buoyant keel 14 is sized and shaped to resist depression. The arrangement provides board 10 with a degree of deliberate instability. That is, the rockered curvature of the hull 12 and the centrally located buoyant keel 14 gives board 10 a tendency to pitch, roll and/or yaw about an axis aligned with the load supporting region. As described herein, by controllably shifting their centre of gravity on load supporting region 18 a rider can cause pivoting motion of board 10, for example for purposes of propulsion and/or steering. By way of analogy, the controlled movements of the rider on deck 16 can be compared to an athlete engaging their core muscles to controllably shift their centre of gravity relative to an unstable exercise ball on which they are at least partially supported.

Unlike conventional surf boards and body boards, board 10 is optimized for self-propulsion. That is, a rider can effectively propel board 10 by using their arms and legs in swimming motions, and/or by shifting the centre of gravity of the core region of their body, rather than relying on waves, current, wind or other external forces for motive force. Further, as described herein, board 10 may optionally be fitted with accessories such as tail fins and the like for translating pitching, rolling and/or yawing movement of board 10 into propulsive force. In some embodiments board 10 is designed so that it is sufficiently short in length (e.g. approximately 5 feet) that it can be easily carried and stowed yet is sufficiently buoyant that a substantial proportion of the rider's weight is supported at or near the water surface in a position that permits use of both the rider's arms and legs using substantially natural swimming motions.

As shown in FIGS. 3-10, in one embodiment primary load supporting region 18 may comprise a rear portion of board 10 which is substantially larger in volume and consequentially substantially more buoyant than the remainder of board 10. More particularly, hull 12 may include a rear portion 22 adjacent a stern end 24 of board 10 which is substantially larger in volume than a forward portion 26 of hull 12 adjacent a bow end 28 of board 10. Therefore the buoyancy of board 10 varies significantly along its length between stern end 24 and bow end 28.

In one embodiment of board 10, hull 12 includes lateral gunnels or side rails 30 which extend longitudinally on opposite sides of hull 12 from rear portion 22 to forward portion 26 (FIGS. 7 and 8). Side rails 30 may extend substantially the entire distance from stern end 24 to bow end 28. In the example of FIGS. 67-74 (described further below), side rails 30 include resilient rail covers 32 to enable a rider to more easily grip rails 30 near bow end 28 and to protect rails 30 from damage. Rail covers 32 comprise a plurality of spaced slots 34 for enhanced slip-resistance. In forward portion 26 of hull 12, side rails 30 have a pronounced upward curve and taper inwardly to merge at a nose 36 of board 10 at bow end 28. As shown in FIGS. 1 and 2, when a rider is positioned on board 10 in a typical riding position in calm water, the terminal height of nose 36 is above the elevation of deck 16.

In some embodiments of board 10, an opening 38 is defined between side rails 30 in forward portion 26 of hull 12 (e.g. FIGS. 5 and 6). As explained below, opening 38 permits a rider to see through forward portion 26 of hull 12 to visualize the water conditions beneath board 10. In some embodiments opening 38 may be covered with a transparent or semi-transparent window 40. In other embodiments, opening 38 may be omitted and forward portion 26 of hull 12 may be enclosed between side rails 30. In a further embodiment, forward portion 26 of hull 12 may include a central member 42 extending along a longitudinal centerline of board 10 between side rails 30. As shown in FIG. 5, central member 42 may subdivide opening 38 into first and second lateral portions 38A and 38B. The thickness of rails 30 and central member 38 and the corresponding size of first and second lateral portions 38A, 38B may vary. In the embodiments of FIGS. 51-74 (described further below), central member 42 is omitted and opening 38 is not subdivided.

Rear portion 22 of hull 12 includes an enlarged body 44 located between side rails 30. In one embodiment, body 44 may be generally oval-shaped or teardrop-shaped in side profile (FIGS. 7 and 8). Throughout most of its length, body 44 provides hull rear portion 22 with a much larger transverse circumferential dimension or “girth” than hull forward portion 26. Body 44 has an upper surface 46 which defines a platform for supporting deck 16 and lateral side surfaces 48. A rear section of body surface 46 curves downwardly at stern end 24 to form a rounded rear tail 50 of board 10. A forward section of body surface 46 is inclined downwardly to merge with forward portion 26 of hull 12. Lateral surfaces 48 of body 38 also taper downwardly on opposite sides of board 10 to merge with corresponding side rails 30. Optionally, lateral surfaces 48 may taper inwardly to form a recessed portion at the base of body 44 adjacent side rails 30.

As best shown in FIG. 4, hull 12 comprises an undersurface 52 which curves longitudinally from stern end 24 to bow end 28. In the terminology of surf boards, paddle boards and the like, an uninterrupted curve of a hull is known as a continuously curved rocker, or continuous rocker. Alternative embodiments of board 10 may include portions of hull 12 which are flattened. In the terminology of surf boards, paddle boards and the like, this is known as an interrupted rocker. This flattening or interrupting of portions of the overall curve of hull 12 will influence the performance of board 10 when in use, particularly the case where board 10 rocks forward and aft.

As indicated above, the curvature of hull 12 in forward portion 26 is very pronounced. As will be appreciated by a person skilled in the art, the pronounced curvature of hull 12, particularly in forward portion 26, distinguishes it from conventional body boards and surf boards which are substantially flat or have a modest longitudinal rocker.

In an alternative embodiment, hull 12 may also have a lateral rocker. Depending on the degree of lateral curvature of hull 12, a lateral rocker may increase the instability of board 10, requiring more skill and effort for a rider to controllably propel board 10 in use.

In some embodiments of board 10, keel 14 projects downwardly from at least part of hull undersurface 52. In the embodiment of FIGS. 3-10, keel 14 extends along the longitudinal centerline of hull 12 substantially the entire length between stern end 24 and bow end 28. The profile of keel 14, including its length, depth, width, thickness and shape, may vary in different embodiments of board 10.

In the embodiment of FIGS. 3-10, keel 14 follows the arc of hull undersurface 52. As described above, keel 14 may include enlarged portions to confer enhanced buoyancy at specific longitudinal locations thereof. More particularly, keel 14 may include a primary thruster 54 located underneath rear portion 22 of hull 12 and one or more secondary thrusters 56 located forwardly of primary thruster 54. In one embodiment, one secondary thruster 56 may be located underneath the forward end of body 44 where hull rear portion 22 merges with hull forward portion 26 (shown, for example, in FIGS. 7 and 8). Optionally, in another embodiment, a further secondary thruster 56 may project from keel 14 adjacent nose 36 at bow end 28 (FIGS. 43-50).

As shown best in FIGS. 7 and 8, and as described in further detail below, deck 16, rear portion 22 of hull 12 and primary thruster 54 of keel 14 may together comprise elements of primary load supporting region 18 of board 10. As will be apparent to a person skilled in the art, the relative size and shape of the constituent elements of primary load supporting region 18 of board 10 may vary in different embodiments of board 10. For example, in some embodiments the volume or girth of hull 12 in load supporting region 18 could be more streamlined and the size of primary thruster 54 could be enlarged. In other embodiments the girth of hull 12 in primary load supporting region 18 could be enlarged and primary thruster 54 of keel 14 could be reduced in size or omitted entirely. The size of deck 16 could similarly vary or deck 16 could be omitted entirely in alternative embodiments. In some embodiments the vertical dimension of primary load supporting region 18 (e.g. from the riding surface of deck 16 to the bottom of keel thruster 54) exceeds the vertical dimension of other regions of board 10. The proportional size of secondary load supporting region 20, which may include a secondary keel thruster 56, could similarly vary in different embodiments of board 10.

In some embodiments of board 10, primary keel thruster 54 is aligned beneath deck 16 to increase the buoyant up-thrust in primary load supporting region 18 of board 10. As discussed below, secondary thrusters 56 are provided to increase the buoyancy of forward portion 26 of hull 12 at a secondary load supporting region 20 or other selected locations to prevent “nose-diving” of board 10 as it is propelled or maneuvered through water, for example in a pitching motion and/or when the rider assumes a very body-forward riding position on board 10.

The size and shape of keel 14 may vary to alter buoyancy or other performance characteristics of board 10. In order to enhance buoyancy, keel 14 may be relatively thick with a blunted or flat lower surface 58. In some embodiments segments of keel 14 bottom surface 58 may be convexly curved between primary and secondary thrusters 54, 56 (FIGS. 47-48). Keel 14 also includes in some embodiments tapered side surfaces 60 which extend from keel bottom surface 58 to the undersurface 52 of hull 12 (e.g. FIG. 46).

Optionally, keel 14 may include a cover 62 fixedly or removably secured to keel lower surface 58 (for example, as shown in FIGS. 1-2 and 3-10). Cover 62 may include a plurality of longitudinally spaced-apart scales 64 each having a fixed end 66 and a free end 68. In one embodiment cover 62 is formed from a rubberized material. Cover 62 protects keel 14 from in-water damage in the event of contact with rocks, reefs and other hard, abrasive hazards. Cover 62 also protects keel 14 from damage during transport and storage.

Further, cover 62 can alter the performance characteristics of board 10 in water. For example, cover 62 may aid in the forward propulsion of board 10 when the bow of board 10 is elevated and depressed alternately, either by the rider's actions, or by some water conditions, such as choppiness. When the board is articulated forcefully up and down in a vertical plane, such as when performing the butterfly stroke, scales 64 will flare outwards, helping to restrict rearwards movement or ‘slipping’ of board 10, thereby accomplishing some conservation of energy of the rider's efforts, making forward propulsion of board 10 more efficient and coherent. Additionally, a following current, or rip tide, travelling faster than board 10 in the same direction as board 10, may to varying degrees engage scales 64, causing them to flare outwards, thereby increasing the friction of board 10 by way of cover 62, thereby, in turn, increasing the ability of a following current to help propel board 10 in the same direction

As will be apparent to a person skilled in the art, a structure similar to cover 62 could be secured to all or some of the undersurface 52 of hull 12. In one example, this could significantly increase the number of scale 64 available to alter the performance characteristics of board 10.

Deck 16 comprises an upper riding surface of hull 12. In the illustrated embodiments deck 16 is located on body 44 of hull rear portion 22. In some embodiments deck 16 is inclined toward forward portion 26 of hull 12. That is, a longitudinal centerline 70 of deck 16 may extend in a generally linear or curved plane intersecting the upturned curved arc of forward portion 26 (e.g. FIG. 3). In some embodiments lateral portions 72 of deck 16 taper inwardly and downwardly toward longitudinal centerline 70 such that deck 16 has a generally V-shaped or U-shaped profile in transverse section or end elevation (FIG. 9). When a rider is positioned on deck 16 in a prone or semi-prone position the rider's torso may be wedged between deck lateral portions 72 to constrain lateral movement of the rider relative to board 10. As shown best in FIGS. 3 and 5, deck 16 may include a partially rounded rear section 74, a central portion 76 and a forward section 78. In one exemplary riding position, rear section 74 may support the rider's hips; central section 76 may support the rider's lower torso; and forward section 78 may support the rider's chest. However, as explained below, the rider's body position relative to deck 16 may vary depending upon rider characteristics and preference, including body size and shape, motion, speed and swimming strokes desired, and prevailing water conditions. For example, as shown in FIG. 2, a rider may assume a forward riding position on deck 16 where the rider's chest is positioned at the forward end of deck 16 at an elevation approximately level with or below the rider's hips and the rider's head is directly above opening 38. As shown in FIG. 1, the rider's hips are shifted rearwardly to be partly in the water and the rider's chest is somewhat raised. In other possible forward riding positions the rider's thighs may be supported by rear section 74 of deck 12 rather than the rider's hips. In other possible rearward riding positions, the rider's hips may be mostly in the water and the rider's lower torso may be supported by rear section 74 with the rider's chest in alignment with central section 76. As will be appreciated by a person skilled in the art, and as discussed further below, the rider may assume many other riding positions, including positions wherein the small of the rider's back is supported by rear section 74, for example where the rider is using board 10 for back stroke swimming motions.

Thus, depending upon the precise position and weight of the rider, the activity being performed and the waviness of the water, the angle at which board 10 rests in the water will vary significantly. In some riding positions the weight of the rider will ordinarily cause tail 50 to be depressed and nose 36 to be elevated. However, there will be many circumstances where nose 36 is lowered closer to the water surface, for example where the rider adopts a more body-forward riding position. As discussed above, opening 38 (optionally covered by a window 40) enables the rider to see ahead of board 10, even when nose 36 is raised. When nose 36 is in a more lowered position the rider is able to see below the surface of the water to some extent, providing a pleasing sensation to the rider. To that end board 10 may be used by a rider to comfortably view aquatic wildlife or the like.

In some embodiments of board 10 deck 12 may not be inclined toward forward portion 26 of hull 12, or may be inclined at a less pronounced angle than shown in the drawings (e.g. FIGS. 7 and 8). In such cases the rider's chest could be supported in a more upright posture in some swimming positions. In another particular embodiment deck 12 may include depressions or cavities, for example to accommodate the rider's central abdomen or belly.

In some embodiments an upper surface of deck 16 is slip-resistant in nature. This may be achieved through the choice of materials used for deck 16, or by the application of a slip-resistant veneer or coating to the upper surface of deck 16. Deck 16 may also include contours, ridges or additional anti-slip features. In one embodiment deck 16 may include a slip-resistant, purchase-enhancing cover 80 which includes a plurality of spaced-apart transverse ribs 82 defining a plurality of transverse channels 84 therebetween (e.g. as shown in FIGS. 3, 5, 9 and 10). Ribs and channels 82, 84 follow the contour of deck 16 and are inclined toward longitudinal centerline 70. In one embodiment, ribs 82 may be tapered slightly forwardly to help restrain sliding rearward movement of a rider on deck 16. The thickness, contour and configuration of deck cover 80 may vary.

A plurality of apertured tabs 86 may be spaced on the lateral edges of cover 80 to act as gripping points for hoisting a rider on to deck 16 and/or attachment points for securing accessories to board 10. Board 10 may optionally include other attachment points similar to tabs 86. For example, board 10 may include a hook 88 mounted on tail 50. Attachable accessories (not shown) could vary based on performance, safety, and aesthetic preferences. For example, such accessories could include grab handles; locks and chains; tethering leashes; tethering straps or nets; stowage bags of varying size and shape; brackets for holding removable containers; camera mounting brackets; solar panels; rechargeable batteries; solar powered lights, and battery or solar powered location beacons and devices. By way of specific example, a lockable chain could be secured to hook 88 for locking board 10 to a secure structure when not in use.

In some embodiments deck cover 80 may extend rearwardly for securement to keel 14, such as primary thruster 54. In one particular embodiment keel cover 62 and deck cover 80 may be one unitary rubberized attachment to board 10.

Optionally one or more tail accessories 90 may be removably connected to a rear portion of keel 14 and/or hull 12 at stern end 24 for extending rearwardly of tail 50 (FIGS. 12-42). For example, as best shown in FIG. 12, in one embodiment tail accessories 90 may be optionally coupled to a mounting slot 92 formed in a rear portion of keel 14. In one particular example, mounting slot 92 may be formed in a rear portion of primary thruster 54 of keel 14 at a point of maximum depth of board 10. As will be appreciated by a person skilled in the art, the size, shape, elasticity and function of tail accessories 90 may vary. Preferably accessories 90 extend behind and below the rider in a manner that will not impede the rider's legs or interfere with kicking motions.

In some embodiments a pair of flexible fin-shaped mounting flanges 94 may be positioned adjacent mounting slot 92 on opposite side surfaces 60 of keel 14 (e.g. FIG. 10). Each flange 94 is secured to hull undersurface 52 and/or keel side surface 60 along an upper edge thereof and has a free lower end adjacent mounting slot 62 to define a narrow opening 96 between keel 14 and a respective flange 94.

When a tail accessory 90 is not in use, a removable plug 98 may be coupled to mounting slot 92. As best shown in FIG. 11, plug 98 includes an insert 100 which matingly fits within slot 92 and a retaining strap 102 having an apertured end 104. End 104 of retaining strap 102 may be secured to hook 88 projecting rearwardly of tail 50 of board 10. Removable plug 98 may thus be coupled to board 10 in a streamlined manner to minimize drag.

In one embodiment shown in FIGS. 12 and 14, tail accessory 90 includes a mounting insert 106, having a shape and profile similar to plug insert 100, which projects from a mounting surface 108. A pair of spaced-apart side surfaces 110 extend from surface 108 on opposite sides of insert 106. Side surfaces 110 are joined by a stretchable mounting strap 112. In the embodiment of FIGS. 13 and 14, side surfaces 110 merge rearwardly of mounting strap 108 to form a single fin 114.

In order to couple a tail accessory 90 to board 10, removable plug 98 is first removed from mounting slot 92. More particularly, retaining strap 102 is disengaged from hook 88 and insert 100 is withdrawn from slot 92. Mounting insert 106 of tail accessory 90 is then inserted into mounting slot 92 and side surfaces 110 of accessory 90 are snugly fitted on opposite sides of keel 14 into a narrow opening 96 defined between a mounting flange 94 and a respective side surface 60 of keel 14. Mounting strap 112 is then stretched over mounting hook 88 of board 10 to secure accessory 90 in place with fin 114 extending rearwardly of tail 50 of board 10. In order to remove tail accessory 90 the above mounting steps are reversed, namely strap 112 is disconnected from mounting hook 88 and insert 106 is removed from mounting slot 92.

FIGS. 15-16 illustrate an alternative embodiment of tail accessory 90 where side surfaces 110 remain spaced-apart rearwardly of mounting strap 112 to form a pair of spaced-apart fins 114. In the illustrated embodiment fins 114 flare outwardly at their rearward end. A person skilled in the art will recognize that the size, shape and orientation of fins 114 may vary in different embodiments.

FIGS. 17-18 illustrate a further alternative embodiment of tail accessory 90 where spaced-apart fins 114 are connected by an adjustable length strap 116 located rearwardly of fixed length mounting strap 112. The length of strap 116 can be adjusted for varying the distance between fins 114 and thereby alter the performance characteristics of tail accessory 90. For example, if board 10 is being used in a following sea where the ocean currents are tending to push board 10 in the desired direction of travel, the rider may choose to lengthen strap 116 to flare fins 114 outwardly to the maximum extent. Conversely, if board 10 is being used principally for wave surfing the rider may opt to shorten strap 116 to draw fins 114 together in order to minimize drag. Additionally, fins 114 may be drawn together or allowed to flare apart by a rider according to their personal physiology or preferred kicking style. For instance, a rider who tends to kick with their legs very close together may choose to adjust strap 116 so that fins 114 are closer together and therefore do not impede the movement of their legs.

By way of example, FIGS. 19-26 show the tail accessory 90 of FIGS. 13-14 secured to a board 10; FIGS. 27-34 show the tail accessory 90 of FIGS. 15-16 coupled to a board 10; and FIGS. 35-42 illustrate the tail accessory 90 of FIGS. 17-18 coupled to a board 10. Such tail accessories 90 may also optionally be coupled to other embodiments of board 10 described herein.

As will be appreciated by a person skilled in the art, a wide variety of other tail accessories 90 may be removably coupled to board 10. For example, a tail accessory 90 could be configured for supporting the legs of a disabled paraplegic rider. In this example, tail accessory 90 could include braces or supports designed to safely and ergonomically support the rider's legs when the rider's torso is positioned on deck 16.

Although tail accessories 90 have been described as being removable, in some embodiments a tail accessory 90 or other extension could be integrally connected to tail 50 of board 10. For example, board 10 could include a permanently mounted rear fin rather than a fin 114 comprising part of a removable tail accessory 90. Conversely, since tail accessory 90 is optional and not essential to the functioning of board 10, it may be removed. For example, many riders may prefer the shorter length and more nimble maneuverability of a board 10 without a tail accessory 90. In another example, board 10 without a tail accessory 90 may be more suitable for use in the close confines of a swimming pool. A rider may also choose to remove tail accessory 90 if they prefer to use a kicking style where their legs could potentially be impeded by accessory 90.

As will be appreciated by a person skilled in the art, tail accessories 90 including fins 114 may be constructed from a wide range of materials and may be either flexible or rigid. In one example accessories 90 are manufactured from materials commonly used in the production of swim fins, flippers and the like and may exhibit varying degrees of flexibility, spring, elasticity, recoil and buoyancy. Depending upon their shape, material, elastic recoil, mounting depth and other features, tail accessories 90 may impart a wide range of performance characteristics to board 10.

Depending upon the particular application or use of board 10, a wide variety of other specialty accessories could be coupled to board 10 in a manner similar to tail accessories 90 or in some other suitable manner. In some specific applications, board 10 could be adapted for use for a variety of lifesaving, search and rescue, and recreational functions. One skilled in the art will understand that mounting slot 92 and/or hook 88 could be used to secure specialty accessories having mating inserts, plugs and/or strap fasteners. Specialty accessories could include, for example, sled runners, skis or boards securely connectable to keel 14 and/or hull undersurface 52 to adapt board 10 for travel over ice or snow. By way of specific example, board 10 could be configured for safe travel over both ice and water (which could be useful, for example, in rescuing an ice skater who has fallen through thin ice). By way of another example, board 10 could be adapted for traversing both snow and water, such as during spring skiing competitions/spectacles where participants slide down a snowy slope and traverse at least partially across a pool of water formed from slushy snow melt. Board 10 could find application in many similar lifesaving, search and rescue, and recreational activities where a rider is called upon to traverse different environmental substrates or conditions, such as water, ice or snow.

Similarly, a specialty accessory could include a wheel assembly for adapting board 10 for travel over land. For example, a plurality of spaced-apart wheels could be coupled to keel 14 and/or hull undersurface 52 for rolling motion on solid ground. In this embodiment, board 10 would have the advantage of supporting the user's torso and legs well above the ground surface for optimal control and safety.

As will be apparent to a person skilled in the art, in some embodiments board 10 could be modified for movement in non-aquatic environments. For example, keel 14 could be omitted entirely and runners, skis, wheels or other ground-engaging supports could be coupled directly to the main body of hull 12.

Other alternative maritime embodiments of board 10 may also be envisioned. As shown in FIG. 84, hydrofoil skegs 118 may be optionally coupled to keel 14 for modifying the ride characteristics of board 10. Under conditions where board 10 is travelling at high speed, hydrofoil skegs 118 will tend to raise board 10 in water and may be suitable, for example, when using board 10 for wakeboarding or when traversing the face of a powerful wave.

FIGS. 75-82 illustrate an embodiment of board 10 configured as a stand-up paddle board, surf board, knee-board, surf-ski, sit-on-top kayak, paddle-ski or the like. In this embodiment the riding position of the rider is ordinarily upright (standing, sitting or kneeling) rather than lying prone. In the illustrated embodiment, hull 12 has an enlarged rear portion 22 located between stern 24 and hull forward portion 26. Hull rear portion 22 supports an enlarged deck 16. As in some other embodiments of board 10 described above, deck 16 may be inclined generally downwardly in a plane intersecting hull forward portion 26. In this example deck 16 is contoured in the shape of a shallow bowl and includes a central platform 120 and a peripheral wall 122 which slopes inwardly toward platform 120. Deck 16 also includes a plurality of spaced-apart upwardly projecting protuberances 124 surrounding platform 120 for bracing the feet or other body parts of a rider. A central bulge or protuberance 125 may also be located within platform 120 (e.g. FIGS. 75 and 77).

As in some other embodiments, board 10 includes a keel 14 extending along the longitudinal centerline of hull 12 and including an enlarged primary thruster 54 aligned below central platform 120 of deck 16 and a secondary thruster 56 aligned below a forward end of deck 16 where rear and forward portions 22, 26 of hull 12 merge (FIG. 79). An enlarged tail accessory 90 comprising a plurality of fins 114 is coupled to primary keel thruster 54, for example in the manner described above in respect of other tail accessories 90.

As in other embodiments, hull 12, keel 14, and deck 16 define a primary load supporting region 18 in a rear portion of board 10. Primary load supporting region 18 has a much larger volume and is consequentially much more buoyant than other regions of board 10. In this example, primary load supporting region 18 supports substantially all of the weight of the rider in an upright riding position rather than a prone or semi-prone position. As shown best in FIGS. 79 and 80, the portion of board 10 of maximum transverse circumferential girth, corresponding to primary load supporting region 18, is aligned with support platform 120. The girth of tail 50 of board 10 at stern end 24 may be reduced.

Since in the illustrated embodiment primary load supporting region 18 comprises a rockered portion of hull 12 and an enlarged, highly buoyant primary keel thruster 54 aligned below deck 16 along the longitudinal centerline of board 10, board 10 is considerably less stable than conventional stand-up paddle boards and the like. That is, the rockered curvature of the hull 12 and the centrally located buoyant keel 14 gives board 10 a tendency to pitch, roll and/or yaw relative to an axis aligned with the primary load supporting region 18. Thus, as in the other embodiments of board 10 described above, a rider can control movement of board 10 at least in part by controllably shifting their centre of gravity on deck 16. Because of the deliberate instability of board 10, more athletic ability and effort will ordinarily be required for a rider to balance in an upright posture on support platform 120 and propel board 10 using a combination of paddling strokes and controlled weight transfer.

For example, in order to propel and steer board 10 of this embodiment, a rider could adopt a standing body position on platform 120 optionally with one or both feet braced against a selected protuberance 124 or 125. Just as a rider may be braced or wedged between lateral portions 72 of deck 16 to maintain a preferred riding position in the embodiments of board 10 described above, in the embodiment of FIGS. 75-82 the rider may be braced in position by engagement with protuberances 124, 125 or by kneeling or sitting within the channels defined between protuberance 125 and peripheral wall 122. While making paddling motions, the rider could shift their weight to a limited extent to initiate pivoting or rocking motion of board 10. This will cause board 10 to pitch forwardly and aft and/or rock from side to side to some extent as it moves through the water. Such movement can apply torque or leverage to fins 114 of tail accessory 90, causing it to impart a propulsive force. Since the centre of gravity of the upright rider in this example is considerably above deck 16, the rider will ordinarily need to engage his or her core abdomen muscles to maintain a stable stance as board 10 is propelled forwardly. Similarly, if board 10 encounters choppy waters or other external forces the rider will need to adopt an athletic stance or risk falling off deck 16. Board 10 thus provides an opportunity for riders to achieve an “all body” work-out in comparison to conventional stand-up paddle boards and the like. As will be appreciated by a person skilled in the art, board 10 can be engineered to achieve boards 10 of differing degrees of instability, such as by varying the size of deck 16, the size or shape of hull rear portion 22, the size or shape of primary keel thruster 54, and/or the size or configuration of fins 114.

If board 10 of FIGS. 75-82 is configured as a surf board, knee-board, surf-ski, sit-on-top kayak, paddle-ski or the like rather than stand-up paddle board the same principles will apply. The rider can position themselves on platform 120 and initiate controlled weight transfer to cause pitching, rolling or yawing movement of board 10, or some combination thereof.

Many variations of board 10 may be envisioned. In the embodiment of FIGS. 3-10 and 19-42, board 10 has a keel 14 comprising one primary thruster 54 and one secondary thruster 56 of a smaller size than primary thruster 54. Primary thruster 54 is aligned with a rear portion of deck 16 and comprises part of the primary load supporting region 18. Secondary thruster 56 is aligned underneath a forward end of deck 16 and comprises part of secondary load supporting region 20. Central member 42 in forward portion 26 of hull 12 subdivides opening 38 into first and second lateral portions 38A and 38B. In this example board 10 either has no tail accessory (FIGS. 3-10) or includes a tail accessory 90 comprising one or more fins 114 (FIGS. 19-42). A forward portion 26 of hull 12 is relatively narrow and comprises a relatively pointed nose 36 having a high terminal height. A board 10 having this configuration would be well-suited for high performance users seeking maximum speed and good trackability.

In the embodiment of FIGS. 43-50 board 10 also has a keel 14 comprising one primary thruster 54 and two spaced-apart secondary thrusters 56 which are each smaller in size than primary thruster 54. Primary thruster 54 is aligned with a rear portion of deck 16 and comprises part of the primary load supporting region 18. In this embodiment, one secondary thruster 56 is aligned underneath a forward end of deck 16 and comprises part of secondary load supporting region 20 (FIGS. 47 and 48). The second secondary thruster 56 is located adjacent nose 36 at bow end 28 of board 10. Central member 42 in forward portion 26 of hull 12 subdivides opening 38 into first and second lateral portions 38A and 38B. In the illustrated example, board 10 does not include a tail accessory 90 although one could optionally be employed. Keel 14 has a modified profile, best shown in side views 47 and 48, where lower surface 58 of keel 14 is concave in segments between thrusters 54, 56, resulting in reduced keel buoyancy, particularly underlying opening 38. This may cause this embodiment of board 10 to slice through choppy waters more effectively.

In the embodiment of FIGS. 51-58 board 10 has a keel 14 with one primary thruster 54 and one secondary thruster 56. Primary thruster 54 is aligned with a rear portion of deck 16 and comprises part of the primary load supporting region 18. Secondary thruster 56 is aligned underneath a forward end of deck 16 and comprises part of secondary load supporting region 20. Secondary keel thruster 56 is considerably larger in volume and substantially more buoyant than in some other embodiments. In this example opening 38 is not subdivided by a central member 42 in forward portion 26 of hull 12. The larger secondary keel thruster 56 can at least partially compensate for the reduced buoyancy of hull forward portion 26. Again, board 10 does not include a tail accessory 90 although one could optionally be employed. This embodiment is similar to the embodiment described above having a forward portion 26 of hull 12 with a narrow profile and a relatively pointed nose 36, but in this embodiment board 10 has a full opening 38 (optionally covered with a transparent or semi-transparent window 40).

In the embodiment of FIGS. 59-66 board 10 has a keel 14 with one primary thruster 54 and one secondary thruster 56. Primary thruster 54 is aligned with a rear portion of deck 16 and comprises part of the primary load supporting region 18. Secondary thruster 50 is aligned underneath a forward end of deck 16 and forms part of secondary load supporting region 20. Secondary thruster 56 is considerably larger in volume and consequentially more buoyant than in some alternative embodiments. In this embodiment hull forward portion 26 has a less narrow profile (i.e. the distance between rails 30 is larger and is more rounded at bow end 28) to increase the size of opening 38 and to provide enhanced stability. Opening 38 is not subdivided and hence provides a large viewing area. The larger secondary keel thruster 56 can at least partially compensate for the reduced buoyancy of hull forward portion 26. Optionally, an upper surface of rails 30 may be covered with a slotted, resilient cover 32 (as shown in FIGS. 67-74) to enable a rider to more easily grasp rails 30 and to protect rails 30 from damage during use as well as transport and stowage. Again, board 10 does not include a tail accessory 90 although one could optionally be employed. A board 10 in this configuration would be well-suited for riders interested in casual pool swimming, underwater viewing, snorkeling and the like. Because of its more rounded nose 36, board 10 of this embodiment may not track as well in some water conditions in comparison to the embodiments having a more pointed nose 36. Some riders may prefer this embodiment for surf riding due to the ease of gripping rails 30 and the option to separate their hands more widely for improved steerability.

Optionally, all embodiments of board 10 may include one or more compartments 126 (FIG. 83) formed in hull 12, keel 14 and/or deck 16. In the illustrated example, compartment 126 is formed in primary thruster 54 of keel 14. Such compartments 126 could be employed, for example, for stowing emergency equipment, cameras, wetsuits, flippers, goggles, sunglasses, clothing, food, drinks or other supplies, or any other items which a rider may wish to stow for possible future access. In some embodiments such compartment(s) 126 may include a water-tight closure 128. One skilled in the art will understand that the size, location, shape and degree of water tightness of compartment 126, and the nature of any associated access hatches, lids or other closures 128, will vary according to preference, nature of application, performance and a wide variety of other considerations. Furthermore, one skilled in the art will understand the importance of ensuring that compartment 126, by virtue of its design, shape, size and degree of water-tightness does not allow for the excessive ingress of water into compartment 126, and will further understand that the inclusion of compartment 126 should not negate the ability of aquatic sports board 10 to support a rider at or near the surface of the water, even should compartment 126 be entirely filled with water.

In one embodiment compartment 126 may be located to permit a rider to add or remove ballast from hull 12, keel 14 and/or deck 16 in order to adjust the weight, floatability, maneuverability or other performance characteristics of board 10.

In some embodiments a cavity or space 130 is defined in forward portion 26 of hull 12 in the space between upturned nose 36 and the forward edge of deck 16 (e.g. FIGS. 6 and 7). If board 10 includes an opening 38 with a covered window 40, space 130 may be defined above window 40. Alternatively if board 10 does not include an opening 38, space 130 may be defined above a surface of hull 12 extending between rails 30 in forward portion 26. Space 130 may function as an ergonomic recess into which a rider may lower his or her head if they choose to (FIG. 2). This may add to the comfort of the rider when performing some activities. For example, a rider may choose to lower their forehead into a lower portion of space 130 when paddling for longer distances, accelerating strongly, or resting in a prone position.

Additionally, one skilled in the art will understand that a variety of cushion inserts (not shown) may be placed in space 130 if desired. For example, such cushions may be custom molded to allow small children and/or pets, under safe and controlled circumstances, to ride comfortably adjacent bow end 28 of board 10 under the close supervision of a responsible adult rider controlling board 10.

As will be apparent to a person skilled in the art, the construction details of board 10 will vary according to both the intended applications and economic considerations, such as the cost of manufacture. For the sake of strength, buoyancy and waterproofing, hull 12, keel 14 and deck 16 are preferably manufactured as one complete whole, but may also be separate components, made of similar or complimentary materials, securely bonded to each other to form an assembled board 10. In some embodiments hull 12, keel 14 and/or deck 16 may be hollow. One skilled in the art will understand that board 10 may be constructed using materials commonly used in surf boards, body boards, paddle boards, kayaks, watercraft and the like. In other words, board 10 is buoyant, water-resistant or waterproof, and manufactured of materials which are of a rigidity, durability and strength appropriate to the intended use.

For example, an embodiment of board 10 intended for use by a serious athlete in a highly rigorous and turbulent marine environment will be constructed of different materials than an embodiment intended for use by children in a swimming pool. Board 10 may be constructed, for example, of a combination of rigid and semi-rigid foams, such as are commonly used in body boards, with a high strength polycarbonate window 40 covering opening 38, and a vinyl, plastic or similar material forming the lower areas of hull 12. An embodiment of board 10 intended for very rigorous use may utilize a combination of high density foam, with a high strength laminate outer shell, and a single sheet of transparent high strength polycarbonate material, such as Lexan™, for the entire bottom of the present invention. In other words, the same high strength, transparent material as is used for window 40 would cover the entire bottom surface of hull 12. Another embodiment of board 10 may use molded plastics or vinyl, using systems common in plastics manufacturing. Another embodiment of board 10 might be intended to be very inexpensive, and for use primarily by children in less rigorous environments, such as swimming pools. Such an embodiment might be made of high density foam with a simple high strength plastic, or vinyl window insert. For certain applications, inflatable versions of board 10 may be produced, using materials and processes currently used in manufacturing inflatable kayaks, paddle boards and pool toys. One skilled in the art will also appreciate, that given advances in the development of industrial materials and manufacturing technologies, new processes of achieving the required strength, water-resistance, buoyancy, weight, and performance characteristics of board 10 may be revealed.

As discussed above, in some embodiments board 10 may include coverings for slip-resistance, purchase-enhancement, damage prevention or other purposes, such rail cover 32, keel cover 62 and deck cover 80. One skilled in the art will appreciate that a wide variety of other covers or moldings may be secured to board 10 for aesthetic, performance, safety or damage-prevention reasons. Such moldings may be made of rubber, plastic, foam, wood, or any other material traditionally used in marine environments. Furthermore, such accessories may be attached either permanently or temporarily, using a wide variety of appropriate means, such as hook-and-loop tape, glue, fasteners, or by means of retaining lugs.

In use, a rider may adopt a wide variety of riding positions on board 10 as discussed above. With reference to FIGS. 2 and 3, in one example the rider is positioned on board 10 in a prone position with the rider's hips located on rear section 74 of deck 16, the rider's lower torso on central section 76 of deck 16, and the rider's chest on forward section 78 of deck 16. In this body position a substantial proportion of the weight of the rider's hips (pelvis) and lower torso (which are typically heavier and less buoyant than the remainder of their body) are supported by primary load supporting region 18 of board 10. That is, the portion of board 10 supporting most of the weight of the rider is sufficiently large in volume and hence sufficiently buoyant to support the rider in an optimum swimming position with the rider's hips raised and the rider's shoulders and chest lowered. In this position the incline of deck 16 helps to maintain the rider's hips at an elevation above or approximately even with the rider's chest (FIG. 2). Since in this riding position the rider's lower torso is supported by primary load supporting region 18, the rider is free to use both their arms and their legs (simultaneously if desired) for propulsion using swimming motions. In at least some riding positions the rider will be supported at an elevation near the water surface somewhat more raised than in conventional swimming. However the swimming strokes used for propulsion of board 10 may be the same or very similar. Thus board 10 facilitates the swimming motions of the rider (or conversely impedes them dramatically less than conventional surf boards, body boards and the like).

More particularly, the relatively narrow width of forward portion 26 of hull 12 enables the rider to move their arms alongside rails 30 of hull 12 in a substantially natural, highly efficient swimming motion. As discussed further below, this is the case whether the rider chooses to use a freestyle, breast stroke, butterfly, back stroke other conventional swimming strokes or hybridized combinations thereof. Further, due to the supported position of the rider's hips and pelvis, the rider can also kick their legs in a substantially natural swimming motion in the water behind board 10 to generate maximum propulsion. Importantly, the power of the kick stroke is maximized without the need for the rider to grasp board 10 with their hands. Also, even if board 10 includes an optional tail accessory 90, fins 114 can be configured to not interfere with the rider's kicking motions as discussed above.

Board 10 is ergonomically designed to comfortably support the rider during use. The V-shaped profile of deck 16 (e.g. FIGS. 3 and 9) wedges the rider in a central position on deck 16 and restrains relative lateral motion of the rider and deck 16 during swimming motions. The slip-resistant cover 80 of deck 16 also helps prevent the rider from shifting position on deck 16 or sliding off deck 16 entirely during swimming motions and/or when choppy water conditions are encountered. As shown in FIGS. 1 and 2, the rider's head can be maintained in a natural swimming posture while enabling the rider to see water conditions in the direction of travel through opening 38 optionally formed in the forward portion 26 of hull 12. As discussed above, opening 38 may be optionally covered by a transparent or semi-transparent window covering 40.

Unlike most prior art aquatic boards or watercraft, the applicant's board 10 is deliberately unstable to some extent. As explained above, the tendency for board 10 to pitch, roll and/or yaw about an axis aligned with primary load supporting region 18 can be usefully controlled and exploited by a rider positioned on at least part of deck 16. For example, in addition to their arms and legs, a rider can use their torso or “core” region of their body to help control and propel board 10. Referring to the riding positions of FIGS. 1 and 2, a rider positioned on deck 16 could elect to use the swimming strokes and kicking motions of the front crawl. As the rider alternates swim strokes on opposed sides of board 10, the rider's torso will have a corresponding tendency to roll from side to side in a manner similar to a natural swimming motion. The rider's core muscles could control the degree and frequency of the rolling movement of the rider's torso which will in turn be imparted to board 10. The swimming stroke and kicks of the rider will propel board 10 forward. Additionally, as explained above, the pitching and/or rocking movement of board 10 may cause the application of torque or leverage forces to structures of board 10 which may also aid in propulsion. More particularly, board 10 may include water-engaging accessories such as rear-facing scales 64, fins 114 or skegs 118 coupled to underside 52 of hull 12 and/or to keel 14 that may acted upon to impart or augment propulsive forces.

By way of another example, a rider positioned on deck 16 could elect to use the swimming strokes and kicking motions of the breast stroke. For this stroke the rider could choose to adopt a somewhat more forward riding position on board 10. Unlike most prior art watercraft, the pronounced upturned profile and narrow width of hull forward portion 26 enables a rider to move their arms in a substantially natural breast stroke movement in the water generally below nose 36 adjacent bow end 28. As the rider engages their core muscles to raise and lower their chest in synchrony with the breast stroke swimming strokes and kicking motions, this motion causes a gentle pitching of board 10 forward and aft which can aid in forward propulsion as discussed above. The rockered profile of hull 12 facilitates this forward and aft pitching. The frequency and extent of this pitching motion is primarily controlled by the rider's movements, although prevailing water conditions may also be relevant (e.g. the choppiness of the water).

By way of another example, a rider positioned on deck 16 could elect to use the swimming strokes and kicking motions of the butterfly. For this stroke the rider could choose to adopt a somewhat more rearward riding position on board 10. This is in turn could cause nose 36 of board 10 to extend at a higher elevation in the water and tail 50 to be depressed. Again, the rider could engage their core muscles to cause more pronounced pitching motion of board 10 as the rider alternatively raises and drops their hips and chest. Again, the frequency and extent of this pitching motion is primarily controlled by the rider's movements, although prevailing water conditions may also be relevant. As in the other examples, forward propulsion may be achieved both by the actions of the rider's strokes and kicks and the translation of pitching, rolling and/or yawing motion of board 10 to water-engaging accessories such as rear-facing scales 64, fins 114 or skegs 118.

By way of another example, a rider could position themselves on deck 16 facing upwards with the small of their back located on or about deck rear section 74. As in other embodiments, the weight of the rider's lower torso is principally supported by primary load supporting region 18. From this posture the rider can propel board 10 forward using substantially natural backstroke motions. As in other examples, forward propulsion may be achieved both by the actions of the rider's strokes and kicks and the translation of pitching, rolling and/or yawing motion of board 10 to water-engaging accessories such as rear-facing scales 64, fins 114 or skegs 118.

As will be appreciated by a person skilled in the art, many other swimming strokes are possible using board 10 such as trudgen, sidestroke, combat sidestroke, doggy paddle, survival travel stroke, oar stroke, moth stroke, or combinations thereof. Many of these strokes will require the rider to adopt different body positions on deck 16. A rider can easily shift position on board 10 depending upon the need for propulsive force, the need to rest, currents, swell and other prevailing water conditions. By way of example, board 10 could be usefully employed by life guards or search and rescue personnel where there is a need for urgent propulsive force, maneuverability in tight or enclosed locations (such as adjacent river banks), usability in both deep-water and shallow conditions, capacity to safely tread water in place, etc.

As explained above, most prior art aquatic boards are not optimized for self-propulsion; instead they are principally configured for riding waves or they require separate equipment, such as sails or paddles, sails, for generating motive force. The applicant's board is configured to support a rider in efficiently achieving self-propulsion. In all of the above examples relating to conventional swimming strokes, board 10 tends to conform to or “mirror” the movements of the rider as it is pivoted or articulated about region 18. Consequently some riders may have a sense that, in use, board 10 is a natural extension or adjunct of their lower torso rather than a separate article to which the rider must necessarily adjust or adapt, such as by modifying their natural swimming strokes or kicking motions. Moreover, the versatility to employ board 10 for both efficient self-propulsion and wave riding applications makes it of use to a wide spectrum of potential riders.

Apart from conventional swimming strokes, many other types of riding positions are possible with board 10. For example, when traversing through shallow water a rider may adopt an extremely forward riding position to raise their legs out of the water altogether. This is possible due to the significantly curved rocker of hull 12, especially in forward portion 26 of hull 12, and the strategically located keel secondary thrusters 56 or other buoyant members which resist depression of hull rails 30 and nose 36. Even in such an extremely forward riding position, the rider may still use their legs and/or lower torso to initiate pivoting motion relative to region 18.

As mentioned, although board 10 is designed for self-propulsion, it can also be employed to ride waves in a manner similar to conventional body boards. For example, in some embodiments a rider could initially adopt a riding position similar to FIG. 1 and use a kicking motion to accelerate board 10 forwardly in anticipation of catching a wave. Upon sensing that the wave has been successfully caught, the rider could then shift their weight forward on board 10 to grasp rails 30 to aid in steering and to pull their legs out of the water to reduce drag. Again, the keel secondary thrusters 56 or other buoyant members at the forward end of board 10 would resist depression and avoid “nose diving” or “pearl diving” even when in such body-forward riding positions.

Thus board 10 supports a rider in a wide variety of riding positions while enabling the rider to pivot or articulate board 10 about a primary load supporting region 18 (located, for example, toward the rear or stern end 24 of board 10). This enables the rider to use their arms, legs, abdominal or “core” muscles, torso and spine in a more natural, powerful and effective way to propel board 10 forward or respond to prevailing water conditions. Thus board 10 is optimized in multiple different ways for efficient self-propulsion.

As explained above, board 10 may also optionally be configured as a stand-up paddle board, surf board, knee-board, surf-ski, sit-on-top kayak, paddle-ski or the like (FIGS. 75-82). As in other embodiments of the invention, board 10 configured as shown in FIGS. 75-82 exhibits deliberate instability which can be controlled and exploited by a rider. In one example a rider could adopt a stance on support platform 120 with their feet side by side. Paddling motion (using a paddle rather than placing the rider's arms directly in the water) coupled with controlled shifting or redistribution of the rider's centre of gravity to cause board 10 to pitch, yaw and/or roll to some extent. As explained above, this motion of board 10 may in turn cause the application of torque or leverage forces to board accessories such as rear-facing scales 64, fins 114 or skegs 118 coupled to underside 52 of hull 12 or to keel 14 to impart or augment propulsive forces. In this example, board 10 includes a very large tail accessory 90 comprising multiple, large manta ray-like fins 114. The periodic application and release of torque forces to tail accessory 90 may cause significant bending and sculling of fins 114, resulting in the application of very substantial propulsive forces.

As described above, board 10 is configured to enable a rider to purposefully and controllably shift their centre of gravity on deck 16, such as by bracing their feet against one or more protuberances 124 or 125 and/or by wedging their knees, shins, buttocks or other body parts in the channels defined between protuberances 125 and an adjacent peripheral wall 122 of deck platform 120. Accordingly, as in the other embodiments of board 10 described above, deck 16 is optimized to enable a rider to gain purchase on deck 16 to safely enable controlled movement. In this example, such purchase is important to enable a rider to shift their upright (e.g. standing) stance rather than to shift the core region of their body in a prone position. For example, a rider could switch between a side-by-side stance and a diagonal stance, in both cases standing astride deck platform 120 and shifting their centre of gravity to cause pitching, rolling or yawing movement of board 10. As will be apparent to a person skilled in the art, a rider could initiate other changes in position relative to deck platform 120 from a kneeling or sitting position, such as in the case of knee-boards or sit-on-top kayaks. By providing surfaces of deck 16 that are not flat, a rider is able to achieve greater purchase and leverage to propel board 10 as desired.

While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions and sub-combinations as are consistent with the broadest interpretation of the specification as a whole. 

1. An aquatic sports board deployable in water and having a bow end and a stern end, wherein said board comprises a buoyant hull having a lower portion which is at least partially curved between said bow end and said stern end, wherein said board comprises a primary load supporting region having a sufficient volume for buoyantly supporting a substantial proportion of the weight of a rider at or near the surface of said water.
 2. The board as defined in claim 1, wherein said primary load supporting region comprises at least part of said hull and has a vertical dimension larger than other parts of said hull.
 3. The board as defined in claim 1, wherein said primary load supporting region has a vertical dimension equal to or exceeding the largest vertical dimension of said hull.
 4. The board as defined in claim 1, wherein said primary load supporting region is substantially larger in volume and more buoyant than other regions of said board.
 5. The board as defined in any one of claims 1-4, wherein said board is pivotable relative to an axis aligned with said primary load supporting region to cause pitching, rolling and/or yawing movement of said board.
 6. The board as defined in claim 3, wherein said primary load supporting region is configured to enable said rider to shift their centre of gravity to cause said movement of said board.
 7. The board as defined in any one of claims 1-6, wherein said primary load supporting region comprises a buoyant member projecting from said lower portion of said hull at a location aligned with a longitudinal centerline thereof.
 8. The board as defined in claim 7, wherein said primary load supporting region comprises a deck for receiving said rider, wherein said deck is located on an upper portion of said hull in alignment with said buoyant member.
 9. The board as defined in any one of claims 7-8, wherein said buoyant member comprises part of a keel of said board.
 10. The board as defined in any one of claims 1-9, wherein said primary load supporting region is configured to support the weight of at least the lower torso of said rider.
 11. The board as defined in any one of claims 1-10, wherein said primary load supporting region is located toward said stern end of said board.
 12. The board as defined in any one of claims 1-11, wherein said primary load supporting region is configured to support said rider in a riding position wherein said rider is able to move their arms and legs through said water to propel said board using swimming motions.
 13. The board as defined in claim 12, wherein, in at least some of said riding positions, said primary load supporting region is configured to support the hips of said rider near the surface of said water at an elevation approximately level with the chest of said rider.
 14. The board as defined in any one of claims 1-13, wherein said primary load supporting region comprises an enlarged portion of said hull which is substantially larger in volume than the remainder of said hull.
 15. The board as defined in claim 14, wherein said hull comprises a rear portion and a forward portion and wherein said enlarged portion of said hull is located in said rear portion.
 16. The board as defined in any one of claim 15, wherein said forward portion of said hull curves upwardly from said rear portion of said hull to a nose located at said bow end of said board.
 17. The board as defined in claim 16, wherein said forward portion of said hull tapers inwardly from said rear portion of said hull to said nose, wherein said forward portion of said hull is substantially more narrow in width than said enlarged portion in said rear portion of said hull.
 18. The board as defined in any one of claims 15-17, wherein said rear portion of said hull has a transverse circumferential girth substantially larger than the corresponding girth of said forward portion of said hull.
 19. The board as defined in any one of claims 15-18, wherein said rear portion of said hull is generally oval-shaped or teardrop-shaped in side profile.
 20. The board as defined in any one of claims 1-19, wherein an undersurface of said lower portion of said hull curves from said stern end to said bow end in a longitudinal rocker
 21. The board as defined in claim 20, wherein said rocker is continuous.
 22. The board as defined in claim 20, wherein said rocker is interrupted.
 23. The board as defined in any one of claim 1-8 or 10-22, comprising a buoyant keel projecting downwardly from at least part of said hull.
 24. The board as defined in claim 23, wherein said keel extends along a longitudinal centreline of said hull.
 25. The board as defined in any one of claims 23-24, wherein said keel extends a substantial portion of the distance between said stern end and said bow end.
 26. The board as defined in any one of claims 23-24, wherein said keel extends continuously from said stern end to said bow end.
 27. The board as defined in any one of claims 23-26, wherein the buoyancy of said keel varies over the length thereof.
 28. The board as defined in any of claims 23-27, wherein primary load supporting region comprises a buoyant member forming part of said keel.
 29. The board as defined in claim 28, wherein said buoyant member comprises a first thruster of said keel having an enlarged volume relative to other regions of said keel.
 30. The board as defined in claim 29, wherein said keel comprises a second thruster located in an intermediate portion of said board between said first thruster and said bow end.
 31. The board as defined in claim 30, wherein first thruster has a larger volume and is more buoyant than said second thruster.
 32. The board as defined in any one of claims 23-31, wherein the width of said keel varies over the length thereof.
 33. The board as defined in any one of claims 23-32, wherein said keel comprises a lower surface and side surfaces which taper outwardly from said lower surface to said lower portion of said hull.
 34. The board as defined in any one claims 30-31, wherein said keel has a third thruster proximate said bow end.
 35. The board as defined in claim 34, wherein said first thruster has a larger volume and is more buoyant than said second and third thrusters.
 36. The board as defined in any one of claims 34-35, wherein a lower surface of said keel has a concave curvature between said first thruster and said second thruster, and a concave curvature between said second thruster and said third thruster.
 37. The board as defined in any one of claims 23-36, wherein a rear end of said hull forming a tail of said board curves downwardly at said stern end and merges with a rear portion of said keel.
 38. The board as defined in any one of claims 1-7 and 9-37, wherein said primary load supporting region comprises a deck located on an upper portion of said hull.
 39. The board as defined in claim 38, wherein deck comprises a rear section adjacent said stern end of said board and a front section located forwardly of said rear section, and wherein at least part of said deck is inclined from said rear section to said front section.
 40. The board as defined in any one of claims 38-39, wherein at least a portion of said deck is inclined inwardly from lateral portions thereof toward a longitudinal centreline of said board, wherein said at least a portion of said deck has a substantially V-shaped or U-shaped cross-section.
 41. The board as defined in any one of claims 38-40, wherein said deck comprises a forward support surface extending along a longitudinal centreline of said deck in a plane intersecting said hull near said bow end.
 42. The board as defined in any one of claims 38-41, wherein said board is sized such that, when the hips of said rider are positioned on said deck, the legs of said rider are free to extend rearwardly of said stern end of said board for propulsion and/or navigation of said board in water.
 43. The board as defined in any one of claims 38-42, wherein an upper surface of said deck is slip-resistant.
 44. The board as defined in any one of claims 38-43, wherein said deck comprises a slip-resistant cover.
 45. The board as defined in claim 44, wherein said cover is removably connectable to said deck.
 46. The board as defined in any one of claims 44-45, wherein said slip-resistant cover comprises a plurality of transverse grooves formed therein.
 47. The board as defined in any one of claims 44-46, wherein said cover comprises a plurality of spaced-apart tabs extending laterally from lateral edges of said deck.
 48. The board as defined in claim 47, wherein at least some of said tabs are aperture for securing an accessory to said deck.
 49. The board as defined in any one of claims 38-48, wherein said hull narrows inwardly from an intermediate portion of said board underlying a forward portion of said deck to said bow end of said board, thereby enabling said rider positioned on said deck in a swimming position to move their arms in the water astride said hull in substantially natural swimming motions.
 50. The board as defined in claim 39, wherein said deck comprises a central section between said rear section and said front section, wherein said central section of said deck is configured to accommodate the torso of said rider between the hips and chest of said rider.
 51. The board as defined in any one of claims 15, wherein said hull comprises first and second opposed side rails on opposite sides of said hull which extend from said rear portion of said hull to said forward portion of said hull.
 52. The board as defined in claim 51, wherein said forward portion of said hull comprises an opening defined between said opposed side rails adjacent said bow end to enable said user to see through said forward portion of said hull.
 53. The board as defined in claim 52, wherein said opening is covered with a window.
 54. The board as defined in claim 53, wherein said window is substantially transparent.
 55. The board as defined in any one of claims 51-54, wherein an upper portion of said side rails in said forward portion of said hull comprise a grip-enhancing covering.
 56. The board as defined in claim 52-55, wherein said forward portion of said hull comprises a central member extending between said rear portion of said hull and said nose between said opposed side rails.
 57. The board as defined in claim 56, wherein said central member subdivides said opening into first and second lateral sections.
 58. The board as defined in any one of claims 56-57, wherein said board comprises a longitudinally extending keel projecting from an undersurface of said hull, wherein a forward portion of said keel projects from said central member.
 59. The board as defined in any one of claim 52-58, wherein said side rails taper inwardly and curve markedly upwardly from said rear portion of said hull to said nose.
 60. The board as defined in any one of claims 51-59, wherein said side rails extend substantially continuously from said stern end to said bow end.
 61. The board as defined in any one of claims 51-60, wherein said board comprises a deck located on an upper surface of said rear portion of said hull for supporting said rider, wherein rear portion of said hull has a width between said side rails greater than the width of said deck.
 62. The board as defined in claim 61, wherein said rear portion of said hull comprises a deck-supporting body extending upwardly from a lower portion of said hull between said side rails.
 63. The board as defined in claim 62, wherein an upper surface of said body has a generally convex curvature.
 64. The board as defined in any one of claims 61-63, wherein said deck is generally oval-shaped in top plan view.
 65. The board as defined in claim 61-64, wherein said deck has a curved forward end proximate said forward portion of said hull and a rear end which curves downwardly conforming to the profile of said rear portion of said hull at said stern end.
 66. The board as defined in any one of claims 1-65, comprising a tail accessory connectable at said stern end.
 67. The board as defined in claim 66, wherein said tail accessory comprises at least one fin.
 68. The board as defined in any one of claims 23-37, comprising a tail accessory connectable to at least one of said hull and said keel.
 69. The board as defined in claim 68, wherein said tail accessory comprises at least one fin.
 70. The board as defined in any one of claims 68-69, wherein said tail accessory is removably connectable to said keel.
 71. The board as defined in any one of claims 68-70, wherein said tail accessory comprises an insert which is removably insertable into a slot formed in said keel and a strap which is securable to at least one of said hull and said keel.
 72. The board as defined in any one of claims 68-71, wherein said tail accessory comprises a pair of spaced-apart flexible fins.
 73. The board as defined in claim 72, wherein the distance between said fins is adjustable.
 74. The board as defined in any one of claim 9 or 23-37, comprising a keel attachment covering at least part of said keel.
 75. The board as defined in claim 74, wherein said keel attachment comprises a plurality of longitudinally spaced-apart scales each comprising a fixed end and a free tail end projecting rearwardly from said fixed head.
 76. The board as defined in any one of claims 1-75, comprising a closable stowage compartment formed in said board.
 77. The board as defined in any one of claims 1-76, wherein said board is a stand-up paddle board and wherein said primary load supporting region comprises a platform on an upper surface of said board for supporting said rider in an upright orientation.
 78. The board as defined in claim 77, wherein said platform comprises a bowl-shaped region comprising a plurality of spaced-apart foot braces.
 79. The board as defined in any one of claim 9 or 23-37, comprising a conversion accessory removably connectable to at least one of said hull and said keel for converting said board for travel over ice, snow or any other non-liquid surfaces.
 80. The board as defined in any one of claims 1-79, wherein said board is semi-submersible, wherein in use a substantial portion of said primary load supporting region is underneath a waterline.
 81. The board as defined in any one of claims 1-80, wherein said board comprises a secondary load supporting region between said primary load supporting region and said bow end, wherein said secondary load supporting region is configured to have a buoyancy less than said primary load supporting region and greater than said other regions of said board.
 82. The board as defined in claim 81, wherein said secondary load supporting region in at least some riding positions is configured to support the upper torso of said rider.
 83. An aquatic sports board comprising: (a) a hull having a rocker which curves from a stern end of said board to a bow end of said board; (b) a keel projecting downwardly from at least part of said hull; and (c) a deck located above a rear portion of said hull for supporting at least a portion of the torso of said user, wherein said deck is configured to enable a user to propel and steer said board using the user's arms and legs.
 84. A personal watercraft comprising a hull having a rocker which curves from a stern end of said board to a bow end of said board, wherein said hull comprises a rear portion for supporting at least a portion of the lower torso of a rider, wherein said rear portion has a substantially larger volume and is consequentially substantially more buoyant in water than other portions of said hull.
 85. A sports board comprising a body which curves from a rear end of said board to a front end of said board, wherein said body comprises a rear portion for supporting at least a portion of the lower torso of a rider, wherein said rear portion has a substantially larger volume than a forward portion of said board.
 86. An aquatic sports board comprising: (a) a hull having a rocker which curves from a stern end of said board to a bow end of said board; and (b) a deck for supporting a rider in an elevated position above a rear portion of said hull, wherein said deck and said hull are configured to support said rider in a swimming position with the rider's hips supported at an elevation approximating the rider's chest.
 87. An aquatic sports board comprising: (a) a hull having a rocker which curves from a stern end of said board to a bow end of said board; (b) a deck located on a rear portion of said hull for supporting a user in a prone or semi-prone position; and (c) a keel projecting from an undersurface of said hull comprising a first thruster located at a position aligned with a rear portion of said deck for supporting the rider's hips and a second thruster located at a position aligned with a forward portion of said deck for supporting the rider's chest.
 88. An semi-submersible aquatic sports board comprising: (a) a hull having an undersurface which curves from a stern end of said board to a substantially upturned nose at a bow end of said board; (b) a deck located on a rear portion of said hull for supporting a rider in a prone or semi-prone position, wherein a support surface of said deck extends in a plane intersecting the curvature of said upturned nose; and (c) a keel projecting from an undersurface of at least part of said hull, wherein said hull, deck and keel buoyantly support said rider in water in swimming positions enabling said user to propel and navigate said board using the rider's arms and legs. 